This is a tale of two Congresses: one that is stuck in the mud and gets no respect, and one where Republican Sen. Richard Lugar of Indiana has been dedicated to trying to keep American foreign policy on track and the country safer. It’s also a tale of a senator whose belief in bipartisanship sticks out like a sore thumb in a party where they wash out your mouth with soap just for talking to Democrats -- and expect serious penance if you vote with them.

For all his pains, and wide respect on foreign policymaking, Lugar now faces a primary challenge from tea partiers who see America’s living in a globalized future as more the devil’s than the Lord’s work.

Author John Shaw’s carefully researched, readable picture of Lugar’s policy oversight shows that bipartisanship and public service need not be oxymorons in a cynical political age. The book highlights his accomplishments. But between the lines is a message about what the loss of consensus and compromise on Capitol Hill, and between Congress and the president, is costing the country as it must deal with sweeping changes in the world.

Twice chairman of the Senate Foreign Relations Committee and nominated for a Nobel Prize on arms control, the six-term senator remembers a Camelot. It was a time when leaders of both parties in Congress schmoozed with each other and the president about policy, and Americans could have at least a rough idea of where the country was headed. But Lugar now sits in a Republican caucus where colleagues bluster about America’s role in the world, sing hymns to shrinking government and cozy up to the same tea partiers who are trying to throw him out of office.

The senator is a policy wonk but also a tiger at following up. He has journeyed four times to the edge of Siberia to assure proper construction of a Russian chemical weapons disposal plant -- including being joined on one trip to Russia by a freshman senator called Barack Obama. And he also can be found poking around in Africa into the safety of laboratories that analyze Ebola, anthrax and other deadly diseases -- to assure that they cannot be converted into biological weapons.

He is courtly and patient but also has a sizable political ego. We have, as Shaw notes, the Lugar Doctrine for national security and the Lugar Energy Initiative. And his name adorns numerous centers and programs back home. He ran for president in 1996 but as a stump speaker would make Mitt Romney look like a hot new Vegas comic. Ronald Reagan eyed Lugar as a possible vice president, as did George H.W. Bush -- who turned instead to Lugar’s obscure Indiana colleague Dan Quayle.

The Indianan has won well over 60 percent of the vote in his last four elections. Yet he now has had to mount a formidable campaign to counter a tea party challenger in the state’s GOP primary in May. Missing from Shaw’s book is what Lugar really thinks about the right-wing takeover of his party and his GOP colleagues’ swashbuckling approach to foreign policy. And it is not clear how much he has had to pull in his own horns on policy because of party pressures. He picks his battles. When Lugar admirer and GOP maverick Chuck Hagel of Nebraska was in the Senate, he pushed Lugar to speak out against the Iraq War. But “after years of softening his criticism and hedging his words,” Shaw writes, the senator only openly challenged the Bush administration on the 2007 surge. It was a far cry from Foreign Relations Chairman J. William Fulbright of Arkansas throwing down the gauntlet to Presidents Johnson and Nixon on the Vietnam War by turning the committee’s hearings on it into a national TV drama.

Lugar did take the Senate Republicans to task in 2010 for dragging their feet on ratification of the second START treaty that further limited nuclear warheads and delivery vehicles. Thanking him, President Obama cited a “direct line” from the trip to Russia he made as a young senator with Lugar to final passage of the arms control agreement. Lugar also worked closely with Vice President Joe Biden when the Democrat chaired Foreign Relations. He has done the same with the current chairman, Sen. John Kerry, D-Mass.

But the GOP’s hard right turn has virtually obliterated the president’s, and Lugar’s, hopes for more centrist cooperation on policymaking. Lugar is a conservative in the same mold as former President George H.W. Bush and former Senate leader Bob Dole, but all have watched helplessly as their own party has been stolen from them.

Shaw notes that Lugar, in his 2004 book Letters to the Next President, wrote, “Too often the motivation for important national security positions of both parties is driven by politics that are disconnected from any credible analysis.” Now both he and the president have had to deal with the Republicans also becoming disconnected from global realities.

Indeed, listening to the current GOP presidential candidates’ bombast about foreign policy must give Lugar an Excedrin headache. As Shaw describes him, the senator is not one to see Washington as a political Gomorrah that needs to be razed in order to be saved. Rather, it is a place where real political leaders can talk softly but carry a big stick, especially on the crucial issues he has concentrated on: controlling weapons of mass destruction, achieving energy independence, preserving the environment, and balancing military and humanitarian concerns in foreign aid.

Lugar should not be treated as a relic of a lost era in politics but rather as a role model for young conservatives. They need to shed their elders’ ideological blinders to deal more pragmatically with major global challenges before they swamp us.

The book’s chief message is that this country needs more people like Lugar, leaders who seek to craft a unified foreign policy so that America can continue to lead in both steady and inspiring ways to confront a whole new world in the making.

[Lewis Wolfson is professor emeritus of communication at American University in Washington and a longtime analyst of Washington, politics and the media.]